The present invention relates to improved means for aligning the side and trailing edges of a set of sheets received in the trays of a sheet sorting or collating machine.
More particularly, the invention relates to such sheet set aligning means in a moving bin sorter which has automatic, in-bin finishing or stapling means for binding the sets of sheets received in the trays before removal of the sets of sheets from the trays.
In-bin stapling sorters as referred to are well known. As exemplified in U.S. Pat. Nos. 4,928,941 and 5,080,342, the sheets may be aligned against a registration surface provided by a standard or frame member or on a bin edge by means of a pusher which is actuated transversely to the direction of the feed of sheets into the trays. The trailing edges of the sheets are aligned by gravity against backstops at the low ends of the sorter trays.
As exemplified in U.S. Pat. No. 5,104,106, a jogger arm has a pusher at one side of the sorter trays to engage a side edge of the sheets and push the sheets towards a registration wall at the other side of the trays, but the arm swings in an arc producing a compound directional force to also bias the sheets towards the backstop at the lower ends of the trays, in an effort to register the sheet edges both laterally and longitudinally of the tray.
In both of the prior art examples of in-bin sorting machines referred to above, the sheets are moved, in each case, to one side of the trays. However, in U.S. Pat. No. 4,949,134, for example, there is disclosed a jogging mechanism which centers the sheets on the trays by movement of a pair of laterally spaced jogging rails towards one another. The rails are moved by racks and separate pinions. The sets of sheets are registered in the other direction by gravity at the low end of the trays.
A pair of opposed jogging rods which move towards one another in arched paths are known from U.S. Pat. No. 3,658,324.
Orbitally movable jogging rods are known from U.S. Pat. No. 3,910,568, wherein the rods laterally move the sheets against a spring loaded alignment bar opposed to the jogging rods. Also orbitally movable jogging rods are known from U.S. Pat. No. 3,250,529 for moving sheets or cards into an aligned set in a corner of a receptacle of a stapler.
These examples of prior art jogging or sheet set edge registering devices are not totally satisfactory or certain in their operation, particularly in the case that sheets have interfacial friction such as may be caused by static attraction between sheets or in the case that the sheets are fed into trays to form sets to be stapled in the trays.
In addition, in the case of in-bin stapling in moving bin sorters, it is necessary to provide for access of the stapler to the set of sheets to be finished. In the prior patent of Uto, et al U.S. Pat. No. 4,928,941, for example, there is disclosed a stapler which can swing to the stapling position in space provided by a combination of vertical space provided by the vertical displacement of the by the tray shifting means and horizontal space provided by horizontal displacement of the trays above the tray in which the stapling is performed. In this arrangement, the main body of the stapler is positioned in a large clearance above the end of the tray in which stapling is performed and the anvil against which the staple is crimped enters a small space between the tray in which stapling is performed and the next lower tray.
In Noto U.S. Pat. No., 4,361,393, Stemmle U.S. Pat. No. 4,687,191 and Cooper U.S. Pat. No. 4,681,310 there are disclosed in-bin stapling sorters of the moving tray type wherein, cams provide plural spaces between the trays for enlarging the sheet entry space between trays as well as for accommodating the body and the crimping anvil of the stapler as it moves into stapling position between the trays from the retracted or non-stapling position.
In Coombs U.S. patent application, Ser. No. 889,633, filed May 28, 1992 co-owned herewith, the jogging of sheets is performed as in the case of U.S. Pat. No. 4,928,941 in that the sheets are moved laterally relative to the direction of infeed into the trays as the trays are moved up and down by the tray shifting mechanism. In this sorter, the tray shifting mechanism does not provide any additional space to accommodate the stapler body, either between trays or longitudinally of the trays, but, instead, the stapler body engages and displaces the sets longitudinally as successive sets of sheets are being stapled in the bins.